PGT - Thanks, I misunderstood the inference of the earlier Subaru / Mobil1 post. I stand corrected. What I have read is that there can be some variation in viscosity in oils with the same rating, such as 5w30, and that Mobil1 tends to have a lower average viscosity than some other 5w30 oils.
That said, anyone who let's their oil go down a quart or two by not checking it frequently is being negligent, and really has only themselves to blame. The only exception to this would be the dipstick-deprived BMW and MB owners, who have to trust the on-board computer for an oil level reading.
It's very unusual to consume a large amount of oil unless there's a specific engine design or specification issue. I've run Mobil1 5w30 in many different cars (Hondas, BMWs, Infinitis, Dodges), and never had an oil consumption issue with any of them, even with high mileage. At most, I'd need to add a half-quart every 2500 miles or so.

 

If you have never needed to check oil levels before (most people get an oil change every 3-5k miles and few motors burn more than a quart in this time) and all the sudden M1 is burning up at a rate of 1 quart per 1-2k miles, I wouldn't call it 'negligence'. I'd call it a product not suitable for it's intended application.

 

So why has this just started happening?

 

the API changed what can be called 'synthetic' and it seems Mobil changed the formulation. They generally use thinner base oils and bring up the viscosity with additives. I've seen posts on other forums where people have called/emailed/written Mobil for an explanation and the standard reply is 'nothing has changed'.

As someone who's exclusively used M1 for over a decade, it's enough uncertainty to decide not to risk it.

 

I've been using Mobil1 5W-30 since 1988. I've never had an oil consumption issue any in vehicle. I ran a 1 ton GMC for 215,000 with no issues, 68K on my MCS with no issues whatsoever. Of course, I check oil levels at minimum once per week. My 2 cents

 

PGT - As I mentioned earlier, I've used Mobil1 for a very long time in a number of different vehicles, and oil consumption has never been an issue. This appears to be a vehicle-specific issue, not a lubrication issue.
As for the supposed Mobil1 formula change, it's another story that everyone has heard, but that no one can verify. I welcome posts by anyone who has detailed, verifiable data or technical analysis on the supposed "old" and "new" Mobil1 formulations, and the formulation differences between the two.

 

But this was done some time ago. Why all of a sudden are we hearing about the problems?

 

Mobil 1 has changed the formulation of their synthetic oils. They are using a "refined" dino oil the meets the current revised definition of synthetic. This new definition was actually taken to court by Mobil 1 after Castrol started using dino oil that was "refined" in a way that they claimed was equal to the properties of full synthetic oils. Mobil 1 lost the court case and thus decided to do the same thing.

Just check out bobistheoilguy.com for a very large amount of info over the years about this controversy.

 

i use mobil 1 and its thin character is why I check the oil level every week.

 

There is nothing on that site, or any others I've seen, that provides any documentation of the supposed "old" or "new" formulations. It's all second-hand supposition and repitition of unsourced claims. Same as this site.

 

I can vouch for that. I used mobil 1 in my 92-x (just a 2.0 wrx in a saab). I would burn oil like I burned fuel, it was very concerning so I switched to royal purple and my issue was solved. And by the way at the time I had not heard about the rod bearing issues at the time.

I have used royal purple ever since.

 

it's old news to me. I'd suspect it's new here because few MINI owners do their own oil service much less use something other than the Syntec MINI recommends.

 

there was a general uproar in the automotive circles I swim in when the definition of "synthetic" was changed. Same thing happened with the definition of "organic".... Guess what was behind both changes... Greed. Skews the market by diluting the definition, makes it harder for consumers to know what they're buying, and allows for those with less rigerous methods to capitalize on the reputation built by others.

In the case of oil, refined dino oil may be as good as the full synthetic, I don't really know, but it is not synthetic, it's refined.

Matt

 

I meant it seems to be new news for the Subie owners.

 

Do a little more reading. It's there.

 

not new for Suby guys.....I remember reading about it when I bought mine in '04 or so or soon thereafter.

 

OK......from my quick review of the linked posts it appeared to be a fairly recent problem.

Wonder if there is any real difference between the 5-30 and the 0-40 Mobil 1 besides viscosity.

 

Hi , only my second post on your forum but the oil conversation is my sort of thing .
I did 16 years with Bp Castrol here in the UK so i have tended to play around with various oils in my 2003 JCW Cooper since I've owned it ( since 04 )
I have now settled on a 5w40 grade after trying various others , i.e 0w30 , 5w30 .. Main problem with these has been that very annoying start up rattle which is totally eliminated by the 5w40 grade .
I would recommend sticking with an ExxonMobil , BP or Castrol grade or in the UK Morris Lubricants of Shrewsbury make a very high quality product.
As far as Subaru is concerned , I had a number of workshop accounts that used ordinary semi synth 10w40 and had no engine issues at all .Many other dealers who used high priced synthetics however were having a couple of cars in a week with engine problems ..So who knows ?

 

Might be interesting to read this link (disclaimer: I do not promote amsoil, in fact, I've never used their products!):
http://www.upmpg.com/tech_articles/motoroil_viscosity/

The interesting thing is to note the viscosity difference between 0C and 100C. For those of you who have experienced oil consumption going to a synthetic, that's easily enough explained. Engine oil temps frequently exceed 100C, especially around cylinder walls and bearings, valve guides, etc. It's very possible that synthetic oils get thinner at the higher temps at different rates, with Mobil 1 being on the thinner side... it's also possible that Mobil 1 has better adherence properties (ability to cling to metal parts), in which case it would explain oil consumption in cars designed with fairly large ring gaps (like turbos) and marginal oil scraper rings. In that case, simply switching to a higher viscosity number (like 5w40, mentioned above) would most likely solve the problem.

You may have also noticed that a lot of older cars (20 years old or older, say) have a lot of problems with leaky seals when using synthetics. The properties of synthetics along with the viscosity variation with temperature will also cause seals to leak, especially main seals. I remember when I first started using synthetic oils in an 89 mustang, the rear main seals started leaking almost immediately, and the car used more oil. I switched to thicker oil (20w50 at the time, I lived down south) and the problem went away.

Btw, I agree, it is despicable that a legal loophole bastardized the word synthetic. Synthetic and refined have very different dictionary definitions, the judge who allowed the mix should've consulted one before rendering his decision. So of course, now we'll have to guess.

As to the OP test link, I've seen the exact same "lever test" performed by those scammers selling teflon engine treatments among others. Sorry, that's a test totally removed from actual engine conditions. I think that at best it proves cold start shear resistance of oil at high pressure contact points (rocker arms, say), and that's about it.

Just my $.02

 

In response to Miniclubmans comments regarding Mobil1, it is the case that there has been a general move away from the 'original PAO based synthetic group 4 base stock mainly for reasons of cost to benefit ratio . It is true that the PAO based products have an overall performance advantage over the now common group 3 hydrocracked ' Synthetics .
However if you look at the area's where PAO's score over hydrocracked its in the extremes i.e stays fluid down to -55 C .. which is great but how many users will ever actually even see -10 C . PAO base stock is now a very expensive commodity here in Europe and supplies are actually becoming unreliable in large volumes . They also say that the latest Hydrocracked base oils are easier to blend with the additive package than PAO's .
The best product Mobil made in my opinion was the original 0w40 which used three base oils . ( Tri Synthetic )

A Synthetic ester ,
A PAO ,
Synthetic Jet aircraft Oil ( Mobil Jet oil 1, I believe )